Commonly assigned application Ser. No. 220,645, filed Dec. 29, 1980, the disclosure of which is incorporated herein by reference, describes a novel technique for the modified in situ retorting of oil shale wherein rubblized beds of oil shale are separately subjected to pyrolysis and combustion. Process gases are supplied to and product gases are withdrawn from each bed, in both the combustion and pyrolysis modes, by a pressure pulsing operation.
In order to carry out the process economically in large horizontal beds or retorts, the beds are arranged in associated pairs and processed oppositely. In other words, while one bed undergoes compression, the other bed in the pair undergoes a corresponding decompression. By this means, pressure pulsing of both beds in the pair can be accomplished using only a single compressor operating full time.
A major cost of the process described in the above-noted Ser. No. 220,645 is due to the extensive mining necessary to form inlet and outlet channels for each bed and the additional lengths of piping required in these channels to carry the product and process gases.
Accordingly, it is an object of the present invention to provide a new bed configuration which will allow significant reduction in the size, length and complexity of inlet and outlet channels and piping needed for carrying out the modified in situ process described in the above-noted application.